BEIRUT -- As fears grow in the West that Syrian President Bashar Assad will unleash chemical weapons as an act of desperation, NATO moved forward Thursday with its plan to place Patriot missiles and troops along Syria's border with Turkey to protect against potential attacks.

Assad's regime blasted the move as "psychological warfare," saying the new deployment would not deter it from seeking victory over rebels it views as terrorists.

The missile deployment sends a clear message to Assad that consequences will follow if he uses chemical weapons or strikes NATO member Turkey, which backs the rebels seeking his ouster. But its limited scope also reflects the low appetite in Western capitals for direct military intervention in the civil war.

The U.S. and many European and Arab countries called for Assad to step down early in the uprising but have struggled to make that happen. Russia and China have protected Assad from censure by the U.N. Security Council, and the presence of extremists among the rebels makes the U.S. and others nervous about arming them.

In Dublin, Ireland, U.S. Secretary of State Hillary Rodham Clinton joined Russia's foreign minister and the U.N. peace envoy to the Arab country for three-way talks that suggested Washington and Moscow were working toward a common strategy as the Assad regime weakens.

The diplomatic efforts to end the civil war come days after NATO agreed to post Patriot missiles and troops along Turkey's southern border with Syria after mortars and shells from Syria killed five Turks.

Germany's Cabinet approved the move on Thursday, and German Defence Minister Thomas de Maiziere told reporters that the overall mission is expected to include two batteries each from the Netherlands and the United States, plus 400 soldiers and monitoring aircraft.

"Nobody knows what such a regime is capable of and that is why we are acting protectively here," said German Foreign Minister Guido Westerwelle.

In Washington, U.S. Defence Secretary Leon Panetta said Thursday that intelligence reports raise fears that an increasingly desperate Assad is considering using his chemical weapons arsenal -- which the U.S. and Russia agree is unacceptable.

The Assad regime said the NATO deployment would not make Assad change course, calling the talk of chemical weapons part of a conspiracy to justify future intervention.

"The Turkish step and NATO's support for it are provocative moves that constitute psychological warfare," Syria's Deputy Foreign Minister Faisal Mekdad said in an interview with Lebanon's Al-Manar TV. "But if they think this will affect our determination and work for a decisive victory in this fight against terrorism, they are very wrong."

Syria has not confirmed it has chemicals weapons, while insisting that it would never use such arms against its own people.

"I repeat for the hundredth time that even if such weapons exist in Syria, they will not be used against the Syrian people," Mekdad said. "We cannot possibly commit suicide."

Analysts say the missile deployment sends a message to Assad to keep the war in his own country.

"There is an element there of deterrence, of coercive diplomacy," said Yezid Sayigh of the Carnegie Middle East Center in Beirut. "We won't go further if you don't go further."

Sayigh said it is possible that Syria, too, moved its chemical weapons to send a counter-message to the West.

Still, the missile deployment does not appear to be a step toward military intervention, he said, noting that no NATO member nations want to enter the war.

NATO officials said the Patriots will be programmed only to intercept Syrian weapons that enter Turkish airspace and will not be fired into Turkey preemptively. This means they would not target Syrian military activities that remain inside Syria.

The German Parliament is expected give its final approval in mid-December, and the Dutch are also expected to approve the move soon, allowing the plan to go ahead. Due to the complexity and size of the Patriot batteries, they will probably have to travel by sea and won't arrive in Turkey for another month.

In Syria, government forces shelled rebellious suburbs around the capital, Damascus. They also clashed with rebels in Damascus as well as in the northern city of Aleppo and elsewhere. Anti-regime activists say more than 40,000 have been killed since the country's crisis started with political protests in March 2011.

The fighting in Syria has enflamed tensions in neighbouring Lebanon, where security officials said the toll in clashes between two neighbourhoods in the northern city of Tripoli had risen to eight dead and more than 60 wounded.

The clashes between the two communities, which support opposite sides in Syria's civil war, started Monday, following reports that 17 Lebanese men were killed after entering Syria to fight alongside the rebels.

The officials spoke on condition of anonymity because they were not authorized to brief the media.